Expression And Significance Of ERβ And HER2 In Breast Cancer Tissue

Objectives:To investigate the expression and significance of ERβ, HER2 in breast cancer. Methods: Samples were obtained from 133 breast cancer and 29 benign breast disease ( BBD ) in 2003. Immunohistochemical method was used to measure the expression of ERβ, HER2.Retrospective study was used. The data were analysed by using chi-square test method. Results: (1) The total expression rate of ERp between BBD and breast cancer was 82.8% (24/29)and 60.9% (81/133)respectively, and the difference was significant (x~2=4.987, P=0.026). The single expression of ERP in BBD and breast cancer was 31.0%( 9 / 29),29.3%( 39/133 )respectively.The coexpression rate of ERβ and ERα arrived at 51.9%( 15/29) , 31.6% (42 / 133) . The ERa and HER2 positive rate in breast cancer were 54.1%(72/133) , 54.1% (72/133) respectively. (2) The ERp positive rate was 47.9%(33/69) for axillary lymph node negative group, 75.0%(48/64) for axillary lymph node positive group .The expression of ERP was correlated with involved lymph node (x~2=10.30, P=0.001, r= 0.275 ). But there were no differences among other clinicopathological characters groups(P>0.05). (3) The level of ERβ protein was associated with HER2 (x~2=4.81, P=0.028,r= 0.187).(4) In breast cancer tissue there was no correlation between ERβ and ERa(x~2=0.77, P=0.380).Conclusions:(1) ERβ widely expresses in breast tissue whether ERa exists or not . The ERβ positive rate in BBD is lower than that in the cancer tissue.So there is relation between the decrease of ERβ expression and breast cancer. (2) In breast cancer tissue the expression of ERp is correlated with involvedaxillary lymph node and HER2.So ERJ3 may be of value to assess the poor prognosis of breast cancer. (3) There is correlation between the expression of ERJ3 and HER2,so ERp is also of value to assess the effect of endocrine therapy. (4) There is no difference between the expression of ERPandERa, so it is necessary to detect ERP in breast cancer.